Winching with greater speed downwardly

ABSTRACT

In a hydraulic crane in which the line or winch speed is usually limited by the output of a positive displacement hydraulic pump, a faster speed downwardly is provided by a valve (preferably foot controlled) which will add to the normal flow in the &#39;&#39;&#39;&#39;down&#39;&#39;&#39;&#39; hydraulic conduit additional fluid from a supplemental source of supply which may be one not always available. The hydraulic fluid provided for another function of the crane, e.g. from a slewing pump, can be used. A check valve prevents reverse flow from the &#39;&#39;&#39;&#39;down&#39;&#39;&#39;&#39; conduit.

United States Patent [72] inventor Wilburn Kelly Brown Morton Grove,Ill.

[21] Appl. No. 741,048

[22] Filed June 28, 1968 [45] Patented July 13, 1971 [73] AssigneePettibone Corporation Chicago, Ill.

[54] WINCHING WITH GREATER SPEED kui ilii sl on ER CV f FUNCTION3,208,221 9/1965 Schuetz 60/97 (P) 3,312,059 4/1967 Stuteville.. 60/97(P) 3,390,785 7/1968 Lado 254/186 3,018,902 1/1962 Minty 212/263,458,053 7/1969 Reuter 254/172 FOREIGN PATENTS 1,007,428 10/1965 GreatBritain i. 254/184 Primary Examiner-Harvey C. Hornsby Attorney-Darbo,Robertson & Vandenburgh ABSTRACT: In a hydraulic crane in which the lineor winch speed is usually limited by the output of a positivedisplacement hydraulic pump, a faster speed downwardly is provided by avalve (preferably foot controlled) which will add to the normal flow inthe down" hydraulic conduit additional fluid from a supplemental sourceof supply which may be one not always available. The hydraulic fluidprovided for another function of the crane, eg from a slewing pump, canbe used. A check valve prevents reverse flow from the down conduit.

PATENTED JUL 1 3 l97l 3; 592 346 2 OTHER cvi FUNCTlON Inventor wliburn.Kellg Brown.

WINCHING WITH GREATER SPEED DOWNWARDLY BACKGROUND OF THE INVENTION Thisinvention relates to an improvement in the manufacture and function ofhydraulic cranes. It is particularly advantageous when used with craneshaving long booms requiring payout of long lengths of line. In suchcranes the speed with which the line is paid out is usually limited bythe output ofa positive displacement hydraulic pump. Excess size in suchpumps would be costly, and they accordingly tend to be chosen of a sizewhich will fully utilize the engine horsepower in raising a maximumload.

It is an object of this invention to provide a crane capable of winchingwith greater speed downwardly. Another object of this invention is toprovide more uniform horsepower utilization comparing that of the cranewhen winching upwardly and when winching downwardly.

SUMMARY In accordance with this invention a faster winching speed, e.g.downwardly, is provided by an operator-controlled valve which, withoutappreciable other cost, connects to the winching hydraulic conduit asupplemental source of hydraulic fluid. Typically the supplementalsupply is a supply needed anyway for another purpose, even though notalways available. This supplemental source of fluid can be the bypasshydraulic fluid from another idle function of the crane, e.g. theslewing mechanism; or it could even be the fluid used in such otherfunction and hence of lower pressure. The presence of a check valve inthe supplemental supply line prevents reverse flow from the main down"conduit.

DESIGNATION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a perspective viewof a truck-borne hydraulic crane of the type in which this invention isparticularly advantageous.

FIG. 2 is a schematic diagram showing a relationship between variousmechanical and hydraulic components which is in accordance with thisinvention.

DESCRIPTION OF PREFERRED EMBODIMENT Although the following disclosureoffered for public dissemination in return for the grant of a patent isdetailed to ensure adequacy and aid understanding, this is not intendedto prejudice that purpose of a patent which is to cover each newinventive concept therein no matter how others may later disguise it byvariations in form or additions or further improvements. The claims atthe end hereof are intended as the chief aid toward this purpose; as itis these that meet the requirement of pointing out the parts,improvements, or combinations in which the inventive concepts are found.

FIG. 1 illustrates a truck-borne crane having a telescoping boom 11 inwhich the hydraulically controlled sections 13 and 14 telescope in andout of the bottom boom section 12. When the boom is in its fullyextended condition, the loadsecuring device such as the hook 16 may berequired to travel repeatedly from a considerable height.

FIG. 2 is a schematic diagram showing various mechanical and hydrauliccomponents involved in the paying out and reeling in of the winch linein accordance with this invention. Conventionally hydraulic fluid fromreservoir 20 is supplied at high pressure by a positive displacementpump 21 to valve mechanism 22 which is manually operated by handle 23.Unless otherwise indicated the valves and pumps referred to in theschematic diagram are entirely conventional and the details of theirconstruction will hot be discussed at length herein. In normal operationwhen handle 23 is in a position which permits no passage of hydraulicfluid to or from hydraulic motor 24 the high-pressure fluid is returnedto reservoir 20 in return conduit 25. When valve handle 23 is in theposition which causes the up movement of hook 16 the high-pressurehydraulic fluid goes to hydraulic motor 24 by way of up conduit 26 andis returned from hydraulic motor 24 by way of down" conduit 27.Returning hydraulic fluid goes through valve 22 and return conduit 25 toreservoir 20. When control handle 23 is in the position which causes thedown" movement of hook l6, high-pressure fluid from pump 21 goes throughdown conduit 27 to hydraulic motor 24 and returns to the valve throughup" conduit 26 and to the reservoir 20 by way of return conduit 25. Apilotactuated check valve 28 in the line 26 prevents discharge frommotor 24 in the loadlowering direction unless it receives apredetermined pilot" pressure from line 27, such as 400 pounds.

Operation of hydraulic motor 24 rotates worm gear 30 and worm wheel 31meshed therewith. Worm wheel 31 is fixed to shaft 32 which is carried bybearing means 33. Fixed onshaft 32 is winch reel 34 which in turncarries the line or cable 15. Hence when the handle 23 is in the upposition the motor 24 is driven in such a direction that the reel 34reels-in cable 15. The opposite is true when handle 23 is in the downposition.

Other functions of the crane such as boom extension, slewing motion,i.e. side-to-side swing of the boom, and boom elevation and lowering arehydraulically powered by hydraulic fluid passing from reservoir 20through conduit 40, pump 41, conduit 40 and valve 42. Each such otherfunction may be controlled by a hydraulic motor 46 which may be a rotarymotor or a cylinder and piston. Valve 42 is intended to represent eithera single valve or a valve bank, controlling one or more other functionsof the crane. Valve 42 (or each valve of the bank) is operated by ahandle 44. Valve 42 is preferable of the power beyond" type. Hence, whenvalve 42 is in the off" position the hydraulic fluid is bypassed. Whenit has passed the last manual valve that may use it, it flows throughconduit 43 which heretofore has lead directly to the reservoir 20. Whenhandle 44 is in on position, fluid passes to a hydraulic motor (notshown) and returns through valve 42 through a return conduit, perhapsseparate from conduit 43, to reservoir 20. In the schematic showingconduit 43, therefore, represents any conduit returning fluid from valve42 to the reservoir, whether spent fluid or power-through fluid.Reservoir 20 is shown at two different locations on the schematicdiagram. This is a mere schematic convenience, a single tank beingcontemplated. All pumps are driven by the crane engine, here shown asthe truck engine'48 (FIG. 1).

All the components designated by numbers less than 50 in the drawingillustrate components which have been in conventional use. Componentsdesignated by the number 50 and numbers greater than 50 are added inorder to provide the improvement in accordance with this invention.

In accordance with this invention valve 50 is interposed in the bypassor return conduit 43. Alternative possibilities, less desirable, are forit to interrupt conduit 40 or to be connected with some other low-costsource of hydraulic fluid under pressure, perhaps lower than thatavailable from pumps 21 and 41. Valve 50 is controlled by anoperator-operated control such as foot pedal 51. Valve 50 includesresilient means such as spring 52 for automatically returning the valvesetting to its passthrough condition whenever pressure is not applied tofoot pedal 51. Hence, when pressure is not applied to foot pedal 51 thefluid in conduit 43 passes freely directly through the valve in itsnormal passthrough circuit, e.g. to reservoir 20 by way of conduit 43.Because it passes freely, it is then at low pressure. When the operatinglever mechanism, e.g. foot pedal 51, is moved the hydraulic fluid inconduit 43 is shunted through conduit 53 to the winch down" conduit 27which supplies hydraulic fluid to winch motor 24. Connected in conduit53 is check valve 54 which permits fluid flow into the down" conduit 27,and prevents return of hydraulic fluid from the main down" conduit 27.

Hence, in the operation of the improvement of this invention the amountof hydraulic fluid supplied to hydraulic motor 24 is not limited by theoutput capacity of pump 21 during the downward winching or line payoutfunctions. When, in accordance with the use of this invention, the footpedal 51 is depressed during the downward winching or line payoutfunction, additional hydraulic fluid is supplied to the hydraulic motor24.

When in accordance with a preferred embodiment of this invention, fluidpasses from a slewing control valve 42 into conduit 43, particularlywhen valve 42 is in the of position and the hydraulic fluid passesthrough the power beyond" or bypass conduit, depression of pedal 51causes valve 50to divert the returning fluid in conduit 43 into conduit53. It is apparent that the supplemental fluid is then available to thewinch hydraulic circuit. In accordance with this preferred embodimentthe pressures which re potentially available from this supplementalsource are substantially the same as the fluid pressures which repotentially available to the slewing motor. During down winching thepressure is usually lower, however, because the winch, doing no work atthis time, does not develop much back pressure.

In accordance with this invention, part of the potential power availablefrom the other function pumps which are operating even though the otherfunctions are idle is utilized to increase the down speed of the winchline. The engine driving the pumps also has power available at this timebecause it is not doing the work of pumping against maximum pressure.Hence, my invention utilizes more of the available horsepower when aload is being lowered and the "other functions" are idle. In accordancewith my invention this is preferably achieved without providing morepumps than are already present on the crane.

Valve 50 must not be so connected that when it is operated the output ofpump 41 would not be protected by a pressure relief valve. Protectionunaffected by valve 50 is represented in the drawing by pressure reliefvalve 55. Such a relief valve is always provided and it is merelynecessary to make sure that is discharge is not through valve 50.

In conjunction with the improvement of this invention, an engineer maychoose for worm 30 and worm wheel 31 a high ratio and low lead anglewhich will make it fully self'locking, thus giving even greater safetythan does valve 28. When lifting heavier loads seems more important thanspeed of lift, the increased down speed of this invention may make thischoice attractive.

ACHIEVEMENT Whether or not the special option just mentioned is chosen,this invention permits attainment of a faster downs'peed, when deemedsafe, with almost no additional expense except that cost of valve 50 andthe foot pedal for operating it. In the preferred form, using thepositive displacement pump provided for another function, no change isneeded in safety features such as the pilot-actuated check valve 28.

I claim:

1. A crane including a raisable, swingable, extensible boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, valves with manual levers for controlling,respectively, the raising, swinging and extension ofthe boom and thewinding of the winch, an engine, a first relief-valved positivedisplacement pump means driven by the engine for winding the wincheither way at will under control of one of said valves and of a size tosubstantially utilize the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; adown conduit for carrying fluid from the winch control valve to thewinch motor, a second conduit serving as a return conduit for carryingsaid fluid back to he valve, a pilot-actuated check valve preventing thereturn of the fluid in said return line except when subjected to asubstantial pilot pressure from the down line; and a secondrelief-valved positive displacement pump of large capacity having itsoutput controlled by at least one of said valves other than the winchcontrol valve, characterized by:

a foot-operated high-speed-down valve for connecting flow from saidsecond pump to said down line to increase the speed of lowering a loadand more nearly utilize the horsepower available from the engine whenthe lowering of a load results in utilizing the full output of the firstpump means at a pressure far below the maximum and at consequentlyreduced pumping horsepower, the high-speeddown valve being incapable ofuse for connecting its second pump to said second conduit for raising aload.

2. A boom and winch apparatus for a crane including a movable boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, a manual winch control valve, boom control valve meansfor controlling movement of the boom, an engine, a first relief-valvedpositive displacement pump means driven by the engine for winding thewinch either way at will under control of said winch control valve andof a size appropriate for the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; adown" conduit for carrying fluid from the winch control valve to thewinch motor to drive the winch in a load-lowering direction, a secondconduit serving as a return conduit for carrying said fluid back to thevalve, a pilot-actuated check valve preventing the return of the fluidin said return conduit except when subjected to a substantial pilotpressure from the down line; and a second relief-valved positivedisplacement pump of large capacity having its output controlled by saidboom control valve means, characterized by:

a foot-operated high-speed-down valve for connecting flow from saidsecond pump to said down line to increase the speed of lowering a loadand more nearly utilize the horsepower available from the engine whenthe lowering of a load results in utilizing the full output of the firstpump means at a pressure far below the maximum and at consequentlyreduced pumping horsepower, the high-speeddown valve being incapable ofuse for connecting its second pump to said second conduit for raising aload.

3. A boom and winch apparatus for a crane including a movable boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, a manual winch control valve, boom control valve meansfor controlling movement of the boom, an engine, a first relief-valvedpositive displacement pump means driven by the engine for winding thewinch either way at will under control of said winch control valve andof a size appropriate for the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; adown conduit for carrying fluid from the winch control valve to thewinch motor to drive the winch in a load-lowering direction, a secondconduit serving as a return conduit for carrying said fluid back to thevalve, a pilot-actuated check valve preventing the return of the fluidin said return conduit exceptwhen subjected to a substantial pilotpressure from the down line; and a second relief-valved positivedisplacement pump oflarge capacity having its output controlled by saidboom control valve means, characterized by:

an operator-operated high-speed-down valve for connecting flow from saidsecond pump to said down line to increase the speed of lowering a loadand more nearly utilize the horsepower available from the engine whenthe lowering of a load results in utilizing the full output of the firstpump means at a pressure far below the maximum and at consequentlyreduced pumping horsepower, the highspeed-down valve being incapable ofuse for connecting its second pump to said second conduit for raising aload.

4. A boom and winch apparatus for a crane including a movable boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, a manual winch control reversing valve, boom controlreversing valve means for controlling movement of the boom, by changesin connections of its controlled ports to fluid supply andreturn-fromvalve conduits, an engine, a first relief-valved positivedisplacement pump means driven by the engine for winding the wincheither way at will under control of said winch control valve and of asize appropriate for the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; adown" conduit for carrying fluid from the winch control valve to thewinch motor to drive the winch in a load-lowering direction, a secondconduit serving as a return conduit for carrying said fluid back to thevalve, a pilot-actuated check valve preventing the return of the fluidin said return conduit except when subjected to a substantial pilotpressure from the down line; and a second relief-valved positivedisplacement pump oflarge capacity having its output controlled by saidboom control valve means, characterized by:

an operator-operated high-speed-down valve for connecting necting itssecond pump to said second conduit for raising a load.

1. A crane including a raisable, swingable, extensible boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, valves with manual levers for controlling,respectively, the raising, swinging and extension of the boom and thewinding of the winch, an engine, a first reliefvalved positivedisplacement pump means driven by the engine for winding the wincheither way at will under control of one of said valves and of a size tosubstantially utilize the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; a''''down'''' conduit for carrying fluid from the winch control valve tothe winch motor, a second conduit serving as a return conduit forcarrying said fluid back to he valve, a pilot-actuated check valvepreventing the return of the fluid in said return line except whensubjected to a substantial pilot pressure from the down line; and asecond relief-valved positive displacement pump of large capacity havingits output controlled by at least one of said valves other than thewinch control valve, characterized by: a foot-operated high-speed-downvalve for connecting flow from said second pump to said down line toincrease the speed of lowering a load and more nearly utilize thehorsepower available from the engine when the lowering of a load resultsin utilizing the full output of the first pump means at a pressure farbelow the maximum and at consequently reduced pumping horsepower, thehigh-speed-down valve being incapable of use for connecting its secondpump to said second conduit for raising a load.
 2. A boom and winchapparatus for a crane including a movable boom, a load-lifting linehanging from the boom, a hydraulic-motored winch for winding the line, amanual winch control valve, boom control valve means for controllingmovement of the boom, an engine, a first relief-valved positivedisplacement pump means driven by the engine for winding the wincheither way at will under control of said winch control valve and of asize appropriate for the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; a''''down'''' conduit for carrying fluid from the winch control valve tothe winch motor to drive the winch in a load-lowering direction, asecond conduit serving as a return conduit for carrying said fluid backto the valve, a pilot-actuated check valve preventing the return of thefluid in said return conduit except when subjected to a substantialpilot pressure from the down line; and a second relief-valved positivedisplacement pump of large capacity having its output controlled by saidboom control valve means, characterized by: a foot-operatedhigh-speed-down valve for connecting flow from said second pump to saiddown line to increase the speed of lowering a load and more nearlyutilize the horsepower available from the engine when the lowering of aload results in utilizing the full output of the first pump means at apressure far below the maximum and at consequently reduced pumpinghorsepower, the high-speed-down valve being incapable of use forconnecting its second pump to said second conduit for raising a load. 3.A boom and winch apparatus for a crane including a movable boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, a manual winch control valve, boom control valve meansfor controlling movement of the boom, an engine, a first relief-valvedpositive displacement pump means driven by the engine for winding thewinch either way at will under control of said winch control valve andof a size appropriate for the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief vaLve; a''''down'''' conduit for carrying fluid from the winch control valve tothe winch motor to drive the winch in a load-lowering direction, asecond conduit serving as a return conduit for carrying said fluid backto the valve, a pilot-actuated check valve preventing the return of thefluid in said return conduit except when subjected to a substantialpilot pressure from the down line; and a second relief-valved positivedisplacement pump of large capacity having its output controlled by saidboom control valve means, characterized by: an operator-operatedhigh-speed-down valve for connecting flow from said second pump to saiddown line to increase the speed of lowering a load and more nearlyutilize the horsepower available from the engine when the lowering of aload results in utilizing the full output of the first pump means at apressure far below the maximum and at consequently reduced pumpinghorsepower, the high-speed-down valve being incapable of use forconnecting its second pump to said second conduit for raising a load. 4.A boom and winch apparatus for a crane including a movable boom, aload-lifting line hanging from the boom, a hydraulic-motored winch forwinding the line, a manual winch control reversing valve, boom controlreversing valve means for controlling movement of the boom, by changesin connections of its controlled ports to fluid supply andreturn-from-valve conduits, an engine, a first relief-valved positivedisplacement pump means driven by the engine for winding the wincheither way at will under control of said winch control valve and of asize appropriate for the horsepower available from the engine whenlifting a load at the maximum pressure permitted by the relief valve; a''''down'''' conduit for carrying fluid from the winch control valve tothe winch motor to drive the winch in a load-lowering direction, asecond conduit serving as a return conduit for carrying said fluid backto the valve, a pilot-actuated check valve preventing the return of thefluid in said return conduit except when subjected to a substantialpilot pressure from the down line; and a second relief-valved positivedisplacement pump of large capacity having its output controlled by saidboom control valve means, characterized by: an operator-operatedhigh-speed-down valve for connecting flow from said return-from-valveconduit to supply fluid therein derived from the second pump to saiddown line to increase the speed of lowering a load and more nearlyutilize the horsepower available from the engine when the lowering of aload results in utilizing the full output of the first pump means at apressure far below the maximum and at consequently reduced pumpinghorsepower, the high-speed-down valve being incapable of use forconnecting its second pump to said second conduit for raising a load.